To identify the anion of an unknown solution, you can perform a series of chemical tests to observe the reactions and use a solubility table to determine the compound.
In this case, you are given Na2CO3 and NaOH solutions, which can be used as a reagent to identify the anions. Let's break down the steps:
1. Test with Na2CO3 solution:
- Add a small amount of the unknown solution to a test tube.
- Add a few drops of Na2CO3 solution to the test tube and observe any changes.
The possible reactions that can occur are:
a) AgCl (Ag+ and Cl-) precipitates from the solution as white curdy precipitate.
b) No visible reaction with NO3-.
By observing the presence or absence of a precipitate, you can infer whether the anion is Cl- (precipitate forms) or NO3- (no precipitate forms).
2. Test with NaOH solution:
- Add a small amount of the unknown solution to a test tube.
- Add a few drops of NaOH solution to the test tube and observe any changes.
The possible reactions that can occur are:
a) Al(OH)3 (Al3+ and OH-) precipitates from the solution as a white gelatinous precipitate.
b) Fe(OH)3 (Fe3+ and OH-) precipitates from the solution as a reddish-brown precipitate.
c) No visible reaction with Cl- or NO3-.
By observing the presence or absence of a precipitate, you can determine the possible cations present in the solution. However, the goal here is to identify the anion, so the observations from the previous test with Na2CO3 are more relevant.
Remember, it is important to consult a solubility table to verify the solubility of the potential precipitates in each reaction. From the solubility table, you can determine which compound is likely to precipitate based on the reaction observed.
By carefully observing the reactions and consulting the solubility table, you can determine whether the anion in your unknown solution is Cl- or NO3-.